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, . „ c R 4 monwealth of Massachusetts Case Study No. 47 

utive Office of Environmental Affairs June 1997 

ujjice of Technical Assistance 


' Pn-77 " U LL| 

. -• COLLECT/ 

OCT. 2 Oi99 8 

Toxics Use Reduction Case Study 

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Korber Hats of Fall River, Massachusetts, a maker of custom straw and felt hats, has 
reduced emissions of volatile organic compounds (VOCs) by 80,000 pounds, 44,000 pounds of 
which was eliminated through process changes and chemical reformulation. The company, which 
was using 52,000 pounds of toluene and 17,200 pounds of methyl ethyl ketone in 1994, 
permanently eliminated the use of these hazardous air pollutants in 1995. Korber has successfully 
substituted a water-based stiffening process in its straw hat dipping operation. Once the company 
and its vendor reformulated a stiffener to a water-based acrylic lacquer, Korber was able to 
eliminate the use of a solvent thinner which consisted of 30% methyl ethyl ketone and 60% 
toluene. '• Korber worked with its supplier to analyze existing coatings and create a new 
formulation which would replace the solvent coating. The company has since successfully 
switched to an entirely water-based process with some process changes and minimal capital 
investment. After adjustments are made for production levels, this project has saved Korber a 
minimum of $36,000 annually in reduced chemical purchases and permitting costs. 


Korber Hats, which employs 50 people, produces more than one million hats per year. 
The major operations performed at the Fall River plant are stiffening, molding, sewing, and 
trirnming. Korber receives the hats into inventory woven and roughly formed. The hats are first 
dipped into coating baths to stiffen and impart water repellency to the final product. They are 
then mechanically molded into shape. The hats are trimmed and sewn to specifications to give 
them their final shape (See Figure 1). The coating step, which is necessary for straw but not felt 
product lines, comprises the majority of chemical use at the facility, so the company's toxics use 
reduction efforts were focused on this process. 





Process Flow Diagram for Straw Hats 






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I Does this \ 


[ product \ 

*■ 1 require a 1 
\ final dip? / 


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Package & Ship 
Final Product 

• . . 



Korber managers first recognized in 1 994 through a self-auditing program that the firm 
was using a substantial volume of coatings containing the hazardous air pollutants (HAPs) toluene 
and methyl ethyl ketone. The company then began intensive research efforts to determine if there 
was a substitute for the solvent-based products used to coat and stiffen the straw hats. Korber 
contacted its supplier, Technical Coatings, and the two companies began to work together to 
develop a low VOC substitute lacquer. Korber Hats worked with Technical Coatings for two 
years to develop and implement the new stiffening process. Technical Coatings made a staff 
person available to Korber to research alternate coating formulations and to spend time at the 
facility troubleshooting the new process. Because of Korber' s commitment to eliminating the 
solvent coating through reformulation, it successfully eliminated use of toluene and methyl ethyl 
ketone (MEK) in 1995. 


Reformulation: Korber's process generally consists of two steps, a pre-dip and a final dip. For 
some products, a third dip is added to impart additional water repellency. The hats are dipped 
in a polymeric coating and then mechanically rotated to remove excess solvent. They are then 
placed on a conveyorized rack and processed through a hot air oven to dry and cure the coatings. 
Starting in 1993 and continuing through 1995, intensive reformulation efforts significantly 
reduced solvent use in the pre-dip. In the autumn of 1994, two new water-based coatings for the 
Panama natural straw hat product line were introduced into production.. The solvent-based pre- 
dip which emitted 630 pounds of VOC for every 100 gallons used was successfully replaced by 
a reformulated pre-dip which emits only 54 pounds of VOC per 100 gallons used. This 
eliminated 20,000 pounds of HAP emissions to the atmosphere. 

Once the company had successfully reformulated the pre-dip, it focused on the search for a water- 
based final dip. Working with its supplier, Technical Coatings, Korber developed a process for 
the Panama straw hat product. line that used only water-based coatings for both the pre-dip and 
final dips. In the past, Korber had used a solvent-based final dip followed by a repellant coating. 
The repellant coating, when prepared for use, was diluted using a ratio of one part product to 
seven parts water. When the company successfully switched to water-based final dip, it found 
it could combine the repellant and final dips into one coating bath, thus eliminating a process 
step. With the entire stiffening process reformulated, Korber was able to reduce its emissions 
significantly. . Now that the company has converted completely to water-based coatings, emissions 
for 1996 have been reduced to approximately two tons annually. 

Process Modifications: Korber had to make modifications to drying ovens, including cure times, 
materials process flow and the pressure used in the molding presses in order to continue 
manufacturing certain product lines at the facility. The company's paper yarn hat product line, 
which consisted of woven recycled paper, deformed when coated with the water-based stiffener. 
Ultimately these hats were converted to water-based coatings, but this product line had to be 
outsourced to a facility with a flat bed drying oven. The change was much more trouble-free for 
hats made of natural straw, the product line on which the new coating was piloted! There were, 
however, several production problems which had to be resolved regarding the finishing of the 
product once it was stiffened. Several changes had to be made to the drying process, including 
incorporating a longer curing time. Fans were also added within the drying oven to enhance the 
curing process of the new coatings. Additionally, the pressing operation which follows the 
coating step required some alteration. As a result of the new coating, the amount of time and 
pressure heeded to form the hats was increased. In fact, the pressure on the molding machines 
had to be more than doubled to successfully mold the hats. 

Because of differences in the flow of materials on the factory floor, there were also some 
improvements made in the configuration of the factory. Additionally, the company had to work 
with its union to reset hourly rates for each of the newly reworked processes. All of these 
adjustments took roughly 12 months to complete. The company has also resorted to outsourcing 
some of the work for those products which needed additional drying, rather than purchasing new, 
larger capacity drying ovens. Korber worked with customers to inform them of the changes to 
their product and found most companies receptive to the change. 


Reductions Achieved: The direct savings from changing the. stiffening solvent to water 
was immediate. Accounting for current changes in production, the savings in reduced chemical 
costs are estimated at $12,000 annually. Korber has eliminated annual costs for handling and 
storage of five to six drums of these hazardous air pollutants. Permitting and engineering costs 
for companies which are major sources of hazardous air pollutants can be conservatively 
estimated at $20,000 annually. Korber has successfully avoided these fees. The company also 
no longer reports under the TURA program for toluene and MEK, saving them more than $4,000 
annually in fees. Although some percentage of the product line had to be outsourced, these 
products were also successfully converted to water-based coatings. Korber' s facility- wide 
emissions have been cut by 22 tons annually. 

This case study is one in a series prepared by the Office of Technical Assistance (OTA), a branch 
of the Massachusetts Executive Office of Environmental Affairs. OTA 's mission is to assist 
industry in reducing the use of toxic chemicals and/or the generation of toxic manufacturing 
byproducts. Mention of any particular equipment or proprietary technology does not represent 
an endorsement of these products by the Commonwealth of Massachusetts. This information is 
available in alternate formats upon request. OTA's confidential, nonregulatory services are 
available at no charge to Massachusetts businesses and institutions that use toxics. For further 
information about this or other case studies, or about OTA's technical assistance services, 
contact: Office of Technical Assistance, 100 Cambridge Street, Room 2109, Boston, 
Massachusetts 02202; phone #(617)727-3260; fax #(617)727-3827; electronic bulletin board 
#(617)727-5621; web site URL: